Manisha Menon wrote:
> Hi all,
>
> I know the question is very silly, but I am sorry I
> could not avoid asking your help.
>
> I follow the MVC design methodology in my web
> framework which has got servlets, jsp and beans.
>
> JSP page forwards the request to the controller
> servlet requesting for a certain action.
> The servlet controller after receiving the request
> object,instantiates the appropriate
> business bean, which will use connection pool manager
> and data access beans for manipulating
> the data. After completing the data handling
> operations, the servlet
> controller returns the manipulated data back to a new
> JSP page.
>
> Now my question :
>
> How is the conversion/ translation of the action (say
> for example updation, insertion or deletion) which is
> coming from the client JSP page done by the controller
> servlet taken to the
> right instance of business bean ? A single page may
> have more than one action. Now, how do the controller
> servlet calls the UpdateBusinessBean for update action
> and InsertBusinessBean for insert action ? The method
> that will be used by the client to invoke the servlet
> is "POST". Can I ask you, what are the possible ways
> of doing this, (Already I have adopted one method in
> my last assignment, but I am not too happy about it,
> as it did not consider scalabilty issues and also it
> was tightly coupled.)
>
> Manisha
>
In a "database maintenance" application like what you describe, it is common to
have a single action class that is called upon to perform slightly different
actions (such as an INSERT for a new row, or an UPDATE for a second).
What I often do in such situations is include a hidden field in the input form that
says one of the following things:
<input type="hidden" name="action" value="Create">
<input type="hidden" name="action" value="Delete">
<input type="hidden" name="action" value="Edit">
depending on which action the user originally asked for. That way, the action
class knows what to do, based on calling:
request.getParameter("action")
to see what was included in the form.
For cases where the user doesn't select which action to perform until the form is
submitted, this field could be set in a JavaScript function, or be chosen by which
submit button was pressed.
Craig McClanahan
===========================================================================
To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff JSP-INTEREST".
Some relevant FAQs on JSP/Servlets can be found at:
http://java.sun.com/products/jsp/faq.html
http://www.esperanto.org.nz/jsp/jspfaq.html
http://www.jguru.com/jguru/faq/faqpage.jsp?name=JSP
http://www.jguru.com/jguru/faq/faqpage.jsp?name=Servlets
